The following species of fossil Balanidæ are given in that most useful work, the ‘Enumerator Palæontologicus’ in Bronn’s ‘Gesichte der Natur:’ it has appeared to me that a few words on each species, might hereafter save others the trouble of searching through several works.

Tubicinella maxima of Morren, said to have been found in the Chalk: this would have been a wonderful fact, considering that no true sessile cirripede has hitherto been found in this formation, and that it implies the existence of Cetacea at this period; but I have been informed that the fossil in question is not a Cirripede.

Diadema bifidum = Coronula bifida of Bronn, in his ‘Italiens Tertiär-Gebilde’ (1831), p. 126 (no Plate). Without a much fuller description I can form no judgment on this species.

Diadema vulgare is probably the Coronula barbara, a Crag fossil described by me.

Pyrgoma undata, Michelotti, in ‘Bull. Soc. Geolog.’ tom. x, p. 141, a mere name without any description: probably it is a synonym of

Pyrgoma sulcatum, Philippi, ‘Enum. Mollusc. Siciliæ,’ which is a synonym of Pyrgoma Anglicum of the present work; found recent and fossil.

Acasta Montagui is probably the extinct Acasta undulata described by me.

Chthamalus giganteus of Philippi, is the Pachylasma giganteum of this work; found recent and fossil.

Chthamalus stellatus, said by Philippi to be found fossil in Sicily; such may be the case, but the littoral habits of the species do not render it very probable.

Balanus carbonarius of Petzholdt, found in the Carboniferous formation! but I have given my reasons, in my ‘Monograph on the Fossil Lepadidæ,’ p. 5, for disbelieving that this is a Balanus, or even a Cirripede.

Balanus ostrearum appears to be a mere name by Conrad, published by Morton in his ‘Synopsis of the Organic Remains of the Cretaceous Group,’ 1834, Appendix, p. 8.

Balanus peregrinus is briefly described and poorly figured, without the opercular valves, by Morton, in his ‘Synopsis,’ ut supra, p. 72, Pl. 10, fig. 5: this Eocene species apparently resembles the Eocene B. unguiformis of Sowerby, described in this work; but quite indispensable details of structure for identification are not given. Another figure of this shell is given in the ‘American Journal of Science’ (N. S.), vol. i, Pl. 2, fig. 6.

Balanus circinnatus, communis, and pustula, of Defrance, as well as all the other species named by him, are described so imperfectly, that the descriptions are of no value whatever, every description being applicable to every species: I must add, that the B. communis is not the B. communis of British authors, a name applied to several forms.

Balanus Finchii is briefly described and figured, but without the opercular valves, by Isaac Lea, in his ‘Contributions to Geology,’ 1833, p. 211, Pl. 6, fig. 222. I do not think that I have seen this species.

Balanus Holgeri, Geinitz, ‘Grundriss der Versteinerungen,’ tab. ix, fig. 19. No opercular valves are given; this species cannot be even approximately recognised.

Balanus proteus, Conrad, ‘Fossil Shells of Miocene Formation of U. States,’ p. 77, Pl. 44 (in ‘Journal Acad. Nat. Sc.,’ Phil., vol. vii, p. 134). I cannot recognise this species; it resembles B. porcatus; but as the radii are rather narrow, and apparently with slightly oblique summits, it may be B. concavus; the opercular valves are not figured.

Balanus sagittata is merely a provisional name without any description, given in a paper on the Crag by S. Woodward, in the ‘London and Edin. Philosoph. Magazine, Brewster, Taylor, and Phillips,’ vol. vii, July-December, 1835, p. 354.

Balanus sublævis, J. de C. Sowerby, in ‘Geolog. Trans.,’ 2d series, vol. v, Pl. 25, fig. 3. Plate extremely imperfect; description extremely short and useless; a species from India not to be recognised.

Balanus balanoides; the species thus named by Ranzani, and found by Philippi in Sicily, certainly is not the true Lepas balanoides of Linn., but may be B. amphitrite of this work. In British collections of Crag specimens I have found the B. dolosus (nov. spec.) thus named: I much doubt whether the truly littoral B. balanoides of Linnæus has been found fossil.

B. costatus of Montagu, a synonym of B. sulcatus of Bruguière, and of B. porcatus of this work; found fossil and recent. This species was originally described by Linnæus under the name of Lepas balanus. But the fossil Lepas balanus of Brocchi is a different species; if it be the same with the recent Lepas balanus of Poli, then it is the B. perforatus of the present work. Again, the B. sulcatus of Bronn, in his ‘Lethæa Geognostica’ (tab. 36, fig. 14), is quite different from the B. sulcatus of Bruguière (i. e., B. porcatus of the present work), as is at once obvious from the oblique summits of the radii. Lastly, B. tesselatus of Sowerby is a synonym of B. porcatus, sulcatus, costatus, and Lepas balanus.

B. punctatus of Montagu is a synonym of Chthamalus stellatus, see remarks on that species: the name of B. punctatus is often applied by British authors to varieties of B. balanoides, see remarks on that species.

B. rugosus of Morris’s ‘Catalogue’ is a synonym of B. crenatus; found recent and fossil.

B. sulcatus of Bruguière, a synonym of B. porcatus; found recent and fossil: see remarks under B. costatus.

B. tintinnabulum of Linn., found recent and fossil; but no trust whatever ought to be placed in the identifications of this species given in several works; thus the Lepas tintinnabulum of Brocchi is distinct. The B. crassus of Sowerby is the true B. tintinnabulum. The B. fasciatus of Dujardin (perhaps only a MS. name) probably is also this species. The B. crispatus is only a variety of B. tintinnabulum.

B. dentiformis, Defrance: see B. circinnatus.

B. ornatus, Münster, ‘Beiträge zur Petrifact.,’ B. 3, p. 29, tab. vi (1840). No opercular valves or details of structure of the several species of Balanus named by Münster, are given, and consequently none can be recognised with certainty.

B. concavus of Bronn, fully described in this work, with the synonyms given; recent and fossil.

B. crassus of Sowerby, a synonym for B. tintinnabulum.

B. latiradiatus, Münster, probably a synonym of B. tintinnabulum, see remarks under B. ornatus.

B. pectinarius, Bronn (‘Italiens Tertiär-Gebilde,’ p. 128), does not appear to me fully enough described to be recognised.

B. pictus of Münster, possibly a synonym of B. amphitrite: see remarks under B. ornatus and balanoides.

B. plicarius, Bronn: see remarks under B. pectinarius.

B. porosus of Hausman (according to Münster of Blumenbach). I cannot recognise this species in Münster’s ‘Beiträge.’

B. pustularis of Lamarck, ‘Animaux sans Vertèbres.’ Scarcely one of the fossil species of Balanus, described by Lamarck, can be recognised; the descriptions are extremely imperfect. There is a figure of B. pustularis in Münster’s ‘Beiträge,’ which makes me think that this may be a synonym of B. concavus of Bronn.

B. pyramidalis, Münster: see remarks under B. ornatus.

B. rhomboicus, Bronn: see remarks under B. plicarius.

B. squamosus, Defrance: see remarks under B. circinnatus.

B. stellaris, Bronn (‘Lethæa Geognostica,’ tab. 36, fig. 13). To this species, Lepas stellaris (I presume a misprint for stellata) of Poli, is given as a synonym; but the Lepas stellata of Poli is a Chthamalus, and this certainly is not the case with B. stellaris. I have received two specimens from the Continent named B. stellaris, but they certainly differed from the form so called by Bronn, for in that, the parietes are said to be porose and the radii very narrow: these foreign specimens I have named B. inclusus. A species described by me as B. corrugatus, resembles in external appearance the B. stellaris of Bronn, but it is mere labour in vain to attempt identifying Balani by their external characters.

B. striatus, Defrance: see remarks under B. circinnatus.

B. tertiarius, Risso, ‘Hist. Nat. de l’Europe Merid.,’ vol. iv. I cannot recognise this species.

B. tesselatus, Sowerby, a synonym of B. porcatus; recent and fossil: see remarks under B. costatus.

B. zonarius, Münster: see remarks under B. ornatus; possibly this is a synonym of B. concavus.

B. amphimorphus, Lamarck: see remarks under B. pustularis.

B. crispatus, var. of B. tintinnabulum.

B. cylindraceus, Lamarck. From Chenu’s ‘Illust. Conch.,’ in which work Lamarck’s original specimens are figured; it appears that this is the B. psittacus of South America, where it is also found fossil, but assuredly Lamarck is quite in error when he states that a variety of this species occurs fossil near Turin. Bronn (in his ‘Italiens Tertiär-Gebilde,’ p. 127) gives as a synonym to the Turin fossil the Lepas tintinnabulum of Brocchi (in the ‘Conchologia Fossile Subapennina,’ t. 2, p. 597), and this probably is correct; and I have hardly any doubt that the Lepas tintinnabulum of Brocchi is the B. concavus of Bronn described in the present work.

B. perforatus of Bruguière is said by Philippi to be found in Sicily: see remarks under B. tulipa.

B. semiplicatus, Lamarck: see remarks under B. pustularis.

B. tulipa of Müller is the B. Hameri of this work, under which name full information on its geological history has been given. The B. tulipa of Poli and Ranzani is the B. tulipiformis of the present work; and this latter species is said by Philippi to occur fossil in Sicily. But there has been so much confusion in the identification of B. tulipiformis, B. Hameri, and B. tintinnabulum, and likewise of B. perforatus (which by Poli was wrongly considered to be L. balanus, Linn.), that doubts must be entertained about which have been really found, until the Sicilian fossils are all carefully examined.

B. ovularis, Lamarck: see remarks under B. pustularis.

B. Uddevallensis, Linnæus, is probably a synonym of the B. Hameri of this work and the B. tulipa of Müller.

[A few other references may be added to those given by Bronn.]

B. miser, stated by Lamarck to be found fossil: see remarks under B. pustularis.

B. patellaris of Lamarck, is stated by Marcel de Serres to be found fossil with several other species of Balanus; thus named without any description in the ‘Annales des Scien. Phys. et Nat. de Lyon,’ tom. i, p. 417.

B. virgatus, delphinus, and crispus, are names given by Defrance, with absolutely worthless descriptions.

B. radiatus is too briefly described by Risso (‘Hist. Nat. de l’Europe Merid.,’ tom. iv, 1826), without a figure, to be recognised; it probably is not the B. radiatus of Spengler, Wood, and other authors.

B. goissopomo, lævis, and radiatus, are mere names without any description, published in a Catalogue by F. Hoeninghaus, in the ‘Jahrbuch für Mineral. Geog.,’ &c., 1831, p. 155.

B. humilis. Conrad, in the ‘American Journal of Science,’ vol. ii (N. S.), p. 400, 1846, has given a short description, with a woodcut, of this species, from the upper Eocene of Florida. The opercular valves are not described, and I doubt whether the species could be recognised.